not only can be replaceable, you can use higher capacity cell (like panasonic 3400mah)

i did once with a old sony FP battery... runs fine till today...

the latest batteries now glow green in the dark....

sorry, but fukushima.....

Steve, did those cylindrical batteries just "pop-out", like any battery retainer in any device? That's truly liberating to know. I had previously "thought" that the packs would have had some form of layered-lithium "pack". This is all too easy, but has to come with all the regular WARNIGS of health & safety and breaking manufactures warranties on devices need to be considered and in light of this, $100, or £100 is cheap insurance, piece of mind and fear of travelling with a non-WARRANTED adaption?

Even so, Steve, a great piece of CSI-type of autopsy.

Grazie

The NP-970 is a nominal 7.4V battery, the camera would certainly not like 17 volts.
I think what's inside the battery is 3 sets of 2x 3.7V cells in series in parallel, the camera is powered directly from that bank of cells, no DC-DC converter is in the battery. All the electronics is protection and charge control of each cell.

@Grazie,
No you cannot pop the cells out and replace them as they're wired in. If you look at the photo you can see where the tabs have been spot welded to the cell.
If you're competent with a soldering iron it is possible to replace the cells although 3rd party NP-970s are so cheap today it's hardly worth the effort.

As for your concerns about safety etc, the only Li-Ion batteries we've had catch fire were genuine Sony ones. The cheap Chinese ones last longer and appear safer. Around 50% of our Sony NP-970 have had the cases come apart exposing the innards.

Bob.

From the Youtube videos I referenced when replacing the cells in my battery pack I was told to NEVER try to solder leads directly onto the cells themselves but instead to buy cell versions that had tabs already spot-welded on, and then solder to those tabs.

I guess lithium-ion chemistry gets a bit upset when it overheats. Ask Boeing.

Farss - you are correct, I also cut open a dead laptop battery and it put out 17V.
The battery is 2-sets of three batteries in parallel providing 7.4 volts total. The center of the two banks went to the PCB, so it has +/- 3.7v going into it.

Riredale - The caution is really because the battery tabs are really difficult to solder to. It could be aluminum but I've tried and you just can't get solder to flow onto it.

I'll keep the parts and possibly try replacing the batteries later. The body of the battery was really destroyed in the process, but knowing what is on the inside will give me a better guide on the next dissection. I used a hacksaw this time, but the next one will be with a Dremel tool to get a cleaner cut.

I see ads in Nuts and Volts magazine from a company who claims they can replace the cells of any rechargeable battery pack. I am tempted to send them a dead NP pack to see if they really can.

The PC board in the battery pack is much more than just a regulator. It is part of the circuitry Sony first used several years ago that quantifies the charge energy and the drain on the battery to inform the camera of available capacity. It is not possible to accurately determine that state of charge of a rechargeable cell simply by measuring the battery voltage. The board contains a small processor that manages the charge process and provides the intelligence to monitor the charging and discharge process. It also takes care of the balancing charge applied to the cells, although it has to be applied to the banks, as the parallel connection does not let them charge individually.

Sony did this to move the sophisticated charge process into the battery to allow them to simplify the battery charger supply system.

It is possible that the cheap Chinese knock-offs do not have such a feature, as some of the ones I have seen do not have the third connection that is used to send data to the camera.

Has anyone found a generic NP-F970 battery that works well?

John

I guess it depends upon what purpose you want it for. I use a number of low cost Chinese knock-offs from Pisen, type QM91D, that only cost about $25 each. I use them mostly for powering LED lights, and so far they are doing a good job.

I don't think that is the same battery as an NP-F970. That battery has 3 pins and is 4500 mAh. The Sony NP-F970 is 6600mAh and has two pins.

John

"Has anyone found a generic NP-F970 battery that works well?"

No. And after one almost disastrous shoot where my #2 called on the intercom - and was in a panic - every battery she had would only run in the camera for a few seconds then the camera stops with the message "Not a genuine Sony InfoLithium battery". I grabbed a new Sony battery and ran to her position and the shoot was salvaged. But we were sweating bullets as I knew the only two working batteries wouldn't last for the whole show. Mine ran out about five minutes before the end, and the #2 camera survived until the final bows. Then it shut itself off.

I got rid of those batteries when I sold my VX-2000 (it didn't care). Now, I use the charger with the DK-415 battery cable on every shoot over an hour long.

I found that the IBS-970 battery from B&H works just fine for about 2/3 the price.
Tom

No. And after one almost disastrous shoot where my #2 called on the intercom - and was in a panic - every battery she had would only run in the camera for a few seconds then the camera stops with the message "Not a genuine Sony InfoLithium battery".

That's pretty funny, the camera throws a hissy fit because you were not using the 'genuine' Sony battery. Actually is a bit of a poor show if the camera then refused to operate. The InfoLithium bit refers to the processor and card I mentioned earlier. It obviously could not communicate with the processor and decided the battery was not 'worthy' as a result.

"the battery was not 'worthy'"

OR

You have not paid the Sony premium!

Bob: As for your concerns about safety etc, the only Li-Ion batteries we've had catch fire were genuine Sony ones. The cheap Chinese ones last longer and appear safer. Around 50% of our Sony NP-970 have had the cases come apart exposing the innards.

I don't have any SONY cameras/batteries so I couldn't make a reply nor comment. I don't have easy access to replacement pieces of camera kit, unless I hire them, and have to get-by on the 3 Canon cameras which I would be loathe to use non-Canon batteries purely on the basis that IF one of the batteries should fail/fire or whatever, I would reasonably like to take my XF300 to the Canon service department and hand on heart inform them of the situation it was used, meaning here, what battery was being used when that battery burst into flames.

As to the spot welding of the batteries, it wasn't clear to me that they were, hence my reasonable question. And yes, I can use a soldering iron.

Grazie

Bob said:
"The cheap Chinese ones last longer and appear safer. Around 50% of our Sony NP-970 have had the cases come apart exposing the innards."
================
Which batteries did you buy? Was it from eBay? Can you post a link?

Thanks Tom for the info on the Ikan IBS-970. The reviews seem really good on that.

John

[I]" Which batteries did you buy? Was it from eBay? Can you post a link?"[/I]

Personally I don't use NP-970s however I've had one of the PL-U95 batteries for almost as long as I've had my EX1. Both the Sony batteries that I bought along with my EX1 are now pretty much dead but the Chinese PL-U95 is still going strong.

There's at least two 3rd party suppliers of 65WH batteries that work directly in the whole PMW line of cameras including the PMW-200. Take your pick really, I chose one over the other to replace one of my Sony batteries because it has a rather fetching red stripe :)

Bob.

"I've had one of the PL-U95 batteries for almost as long as I've had my EX1."
===============
I remember when you bought that battery Bob. I picked up a similar one for my EX1 and it is just as good as the Sony for a fraction of the cost.

NP-F970 I use for several devices including my VX2000 that I still use for certain types of shoots. It's a very common battery. I may get the Ikan IBS-970 that Tom mentioned.

John